It is probably the biggest accounting error in history. China has just discovered that it overlooked about $285 billion in output in 2004. Its economy, at $1,980 billion, is therefore about one sixth bigger than previously estimated. This is an error that would certainly not go unnoticed had it been made by, say, Devon County Council. But China is very big. In fact, its economy overtook Italy’s two years ago, has cruised past France and, with the new figures, has also surpassed Britain. That puts China in fourth place, behind the US, Japan and Germany.

Many Britons would be surprised that the UK economy has held up in the league table for so long. Examine almost any household object today and it will say “Made in China”. Indeed, most children probably imagine that Santa loads up his sleigh with toys on the outskirts of Shanghai. China is swiftly becoming the workshop of the world. The implications are also global: China has a far stronger claim to attend the annual G8 summit of leading industrial powers than Russia. Indeed, its invitation should have gone out five years ago.

Beijing’s statistical blooper may not be as inexplicable as it seems. Any national measurement of GDP is largely an estimate. In China the statisticians were not only working with poor figures but were also bamboozled by thousand of private entrepreneurs, only recently fully legalised and reluctant to report results to officialdom. Hence the underestimate of the service sector, if proportionately far smaller than in other countries. China is still a long way behind Japan, at $4,623 billion or the US at $11,667 billion. But Germany at $2,714 billion? Not long to go.